1. Field of the Invention
The invention relates to an apparatus for welding a wire mesh of longitudinal and transverse crossing wires with a rotatable upper and lower electrode configured as a disc-shaped polygon with at least the upper electrode being movable in upward and downward directions and the upper and lower electrode being rotatable into a working position in which each of the polygonal surfaces is disposed parallel to the longitudinal wires.
2. The Prior Art
From German patent specification 27 26 883, there is known a welding electrode for welding wire meshes which is structured in the manner of a circular ring or polygonal configuration similar thereto, such as an octahedron. The known apparatus suffers from the drawback that no precautions have been made to protect the contact surfaces of the welding electrodes from soiling. A further drawback is that the rounded surfaces of the wires to be welded together are disposed on a planar surface of the welding electrode so that there exists a linear contact only between the wire and the welding electrode.
It is an object of the invention to overcome the mentioned disadvantages and to provide an apparatus of the kind referred to supra which makes it possible to provide welding electrodes for multiple applications and which ensures clean contacting of the wires with the welding electrode.
The apparatus in accordance with the invention is characterized by the upper electrode and the lower electrode being provided at each polygon surface with an internal distribution channel for cleaning air, preferably pressurized air, with each distribution channel being provided with a blow-out opening ending in the center of the polygon surface, and by each of the upper electrode and the lower electrode being associated with a manifold for the cleaning air, each manifold being provided with a connector for feeding of cleaning air and with an internal air channel connected to the connectors and the distribution channels of the of the upper and lower electrode in their working position.
In accordance with a further characteristic of the invention the upper electrode is provided at its circumference with a V-shaped transverse wire groove for receiving the transverse wire during welding, the lower electrode is provided at each polygon surface with a preferably V-shaped longitudinal wire groove disposed parallel to the plane of the longitudinal wire for receiving the longitudinal wire during welding, with each of the blow-out openings terminating in the center at the bottom of the transverse and longitudinal wire grooves.
Preferably, in the case of a plurality of blow-out openings in every polygon surface the blow-out openings are disposed symmetrically in the wire grooves or, if there are no wire grooves, they are also symmetrically disposed in that area of the polygon surface which is the welding position of the wires on the welding electrodes.